Numerical simulation of tangentially injected turbulent swirling flow in a divergent tube

• Published in: International journal for numerical methods in fluids Vol. 61; no. 7; pp. 796 - 809
• Main Authors: Guo, Hui-Fen, Chen, Zhi-Yong
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 10.11.2009; Wiley
• Subjects: Computational fluid dynamics; diverging pipe; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fluid flow; Fundamental areas of phenomenology (including applications); injector; Injectors; Mathematical models; Outlets; Physics; recirculation zone; Rotational flow and vorticity; swirling flow; tangential inlets; Turbulence; Turbulent flow; vortex breakdown; Vortex dynamics; Walls; Divergent pipe; Turbulent flow; Computational fluid dynamics; swirling flow; tangential inlets; Digital simulation; diverging pipe; Vortex breakdown; recirculation zone; Finite volume methods; Injector; Modelling; Vortex flow; Air jet; Spinning; Mesh generation; Turbulence structure
• ISSN: 0271-2091; 1097-0363; 1097-0363
• DOI: 10.1002/fld.1985

This paper studies the properties of turbulent swirling decaying flow induced by tangential inlets in a divergent pipe using the realizable k–ε turbulence model and discusses the effects of the injector pressure and injection position. The results of transient solutions show that both the recirculation zone near the wall in upstream of the injectors and the vortex breakdown in downstream of the injectors increase in size during the whole period. A nearly axisymmetric conical breakdown is formed and its internal structure consists of two asymmetric spiral‐like vortices rotating in opposite directions. The stagnation point shifts slowly toward the pipe outlet over time. The maxima of the three velocity components, which are located near the wall, decrease gradually with streamwise direction. It can also be inferred that Mach number approaches 1.0 near the injector outlets. The velocities increase with the increasing injector pressure. However, its increasing trend is not significant. With the increase of the injection position, vortex breakdown moves in downstream direction and the pitch along the streamwise direction increases. Copyright © 2008 John Wiley & Sons, Ltd.